Arseny Roginsky, the longtime leader of the Russian human rights organization Memorial and a Soviet-era dissident who documented the victims of state persecution during the Cold War and after, died on Monday in Tel Aviv. He was 71.

Memorial announced his death in a news release. He had cancer and had gone to Israel for treatment as his condition worsened, friends said. Israel is a common destination for Russian Jews, like Mr. Roginsky, seeking cancer care.

Mr. Roginsky waged his longest battle with the ghosts of Russia’s past. For almost 30 years he oversaw Memorial’s painstaking campaign to record the names of more than three million victims of Soviet persecution.

Under his leadership, the organization also extended its mandate to confront human rights issues in modern Russia, especially abuses in the restless North Caucasus and in the continuing war in eastern Ukraine. In the process, he helped shed light on the forces to which he himself fell victim in the 1980s as a political prisoner of the Soviet regime.

Mr. Roginsky became Memorial’s official chairman in 1998. By then, the flirtation with liberalism that began under the Soviet leader Mikhail S. Gorbachev had ended. And with the rise of Vladimir V. Putin, whose nationalism depended on a heroic portrayal of Russia’s past, the crimes that Memorial had cataloged had no place in the official narrative.